The present invention relates to a self-propelled, vehicle-mounted conveyor system used to place concrete or other material in a desired location. More specifically, the present invention is a vehicle-mounted conveyor system that includes powered turntables and lifting mechanisms for both the discharge conveyor assembly and the infeed conveyor assembly.
Vehicle-mounted, extendible concrete conveyor systems, such as shown in U.S. Pat. No. 4,624,357, have been in use for some time. Vehicle-mounted conveyor systems of this type have been found to be very useful because the concrete, or other material, can be transferred to a location at the work site that may be located a considerable distance from the supply of the material. The vehicle mounted conveyor system has proven to be very useful since the entire conveyor system can be quickly and easily moved by simply moving the vehicle on which the conveyor system is mounted. The conveyor system not only can be moved around the work site, but also includes a discharge conveyor assembly having a telescoping boom that can be extended and retracted, rotated about a vertical axis, and elevated to considerable heights. The vehicle-mounted conveyor system identified above can be moved from a working position to a stowed position and the entire system can be transported over highways to travel between job sites.
The extendible discharge conveyor assembly of the conveyor system includes a moving discharge conveyor belt that is feed by a second, infeed conveyor assembly. One end of the infeed conveyor assembly is positioned on the ground and receives a supply of concrete from a ready-mix truck or other type of delivery means. The infeed conveyor assembly transfers the material onto the discharge conveyor belt, which transport the material to the desired point at the work site.
In currently available vehicle-mounted conveyor systems, the infeed conveyor assembly is mounted to a swivel mechanism above one end of the discharge conveyor assembly. The swivel mechanism allows the infeed conveyor assembly to be manually rotated about the stationary vehicle to position the infeed conveyor assembly near the ready-mix truck or other delivery means. Typically, the infeed end, or loading point, of the infeed conveyor assembly includes a supply hopper and relatively large wheels that allow the infeed conveyor assembly to be pulled or pushed along the ground at the work site. Although the loading point of the infeed conveyor assembly can be moved to the desired location, the infeed conveyor assembly is typically quite large and heavy, which makes manual movement of the infeed conveyor extremely difficult. Additionally, the unevenness of the ground at the work site makes the movement of the infeed conveyor assembly even more difficult and subject to damage.
Therefore, it is an object of the present invention to provide a vehicle-mounted conveyor system in which the infeed conveyor assembly is mounted to a powered, secondary turntable such that the infeed conveyor assembly can be rotated relative to the vehicle using mechanical power. It is a further object of the invention to provide the secondary turntable between the discharge end of the infeed conveyor assembly and a main turret mounted on the vehicle such that the secondary turntable can be operated to rotate the infeed conveyor assembly on the same vertical axis as the main turret. It is a further object of the present invention to provide a powered, primary turntable positioned between the main turret and the vehicle to rotate the main turret relative to the vehicle. Additionally, it is an object of the invention to permit independent operation of the primary turntable and the secondary turntable, such that rotation of the discharge conveyor assembly and rotation of the infeed conveyor assembly are independent from each other. It is a further object of the invention to provide mechanical lifting mechanisms, such as hydraulic cylinders, that are operable to independently raise and lower the infeed conveyor assembly and the discharge conveyor assembly.